Breaker point grinder



July 11, 1933. H, WALTERS 1,917,863

BREAKER POINT GRINDER Filed Jan. 18, 1932 MTNESS R fih m flTTORNEYS Patented July 11, 1933 UNITED STATESPATENT OFFICE BREAKER POINT GRINDER Application filed January 18, 1932. Serial No. 587,312.

This invention relates to a device for grinding the contact points of electric circuit breakers commonly used in the ignition systems of internal combustion engines as. applied more particularly to automobiles and other motor vehicles and is similar in some respects to that shown in my pending application Serial No. 550,483 filed July 13th, 1931 in that itincludes a rotary shaft mounted upon a suitable supporting frame. and; provided with a grinding disk adapted to be 1nserted between the contact points for grinding the same in parallel relation.

The main object, however, of the present invention is to simplify the construction and at the same time to increase the generalefficiency of the device by provldmg 1t with means adapted to receive one of the contact points and thereby to hold the grinding disk in proper grinding relation to both of the contact points while the disk is being rotated by hand.

In other words, I have sought to provide a device of this character at a sufficiently low cost so that owners of cars may do their own grinding, if desired, and at the same time to permit the device to be stored in any tool receptacle with which the automobile is usually equipped ready for use any time. o

Other objects and uses relating to specific parts of the device will be brought out in the following description.

In the drawing V Figure 1 is a perspective view of the entire 2 device ready for use.

i a hand crank 5 bywhich the shaft may be turned, the other end being threaded at -4-.- and engaged by a suitable nut or bushing 6- which, in turn, is journaled in the adjacent opening -3'-.

One of the arms as 2' is provided with an extension ,7 having an opening 8-- for receiving one of the contact points a1, the other contact point 'a being mounted upon the usual movable member 'b-..which is spring pressed towardthe contact point A relatively thin grinding disk 9 of carborundum, emery cloth or any other suitable material is clamped tothe shaft l... between the innerend of the nut 6 and a shoulder 10 on the shaft to hold said disk in close proximity but in slightly spaced relation to the inner face of the adjacent arm 2. v

v The disk 9 is of sufficient diameter to extend radially across and beyond the opening 8 in the arm .2 so that when the extension 7 isplaced over and upon the adjacent contact point a, the adjacent portion of the disk will be inter-posed between the contiguousfaces of both contact points for grinding purposes. r

The frame 1preferably consists of a single piece of rather heavy wire having its intermediate portion bent in the form of a handle .1' and its opposite ends arranged in parallel spaced relation and preferably flattened to form bearings for the op posite ends of the shaft 4.

The combined thickness of'the extension V 7 and disk 9 is somewhatless than. the distance between the contact points a and -a when the latter are fully opened.

The disk 9 is firmlyclamped between the shoulder 10 and clamping nut -6+ on the shaft 4to rotate with said shaft,

but in case it should be necessary to remove the disk by reason of impairment or other cause, it is simply necessary to, remove the;

clamping nut -6 and then to withdraw the shaft --4 endwise from the arm 2 sufficiently to allow the disk to be removed and another one replaced after which the shaft with the disk thereon may be 'restored'to its operative position and the disk secured in 95 place by the tightening of the nut .-6.

Operation When it is desired to use the device for grinding the breaker points, the latter will lowed to close uponopposite faces of the interposed portion of the grinding disk 9 The shaft 4 with the grinding disk 9 thereon is then rotated by means of the hand crank 5- with the assurance that both faces ofcthe breaker points will be ground in parallel planes.

This operation is continued until the breaker points are properly ground following which theyjwill be opened by hand sufficiently to allow the removal of the eXten sion 7 and disk 9 from between them, it being understood that the entire 'device will beheld in one hand by means of the handle --1 while the shaft -t and grinder are being rotated by the other hand. and that the removal. of theextension -7 and disk '9- from between the points will allow the latter to open and close in the usual manner for circuit breakers of this character.

. It will be noted that the deviceis particularly simple, practical and eflicient and may be manufactured with very little cost, but

U-shaped frame having its base provided obviously various changes may be made in the detail construction without departing from the spirit of the invention.

What I claim is:

1. In a breaker point grinder, a supporting frame having an arm provided with an aperture for receiving one of the breaker points, a rotary shaft operable at will journaled in said arm, and a grinding disk secured to the shaft and extended across said aperture in close proximity to said arm and adapted to be interposed between the breaker points during its rotation.

2. A breaker point grinder as in claim 1 in which the shaft is provided with arela- 'tively fixed shoulder and a removable shoulder between which the grinding disk is clamped. r

3. A breakerpolnt grinder comprising a with a handleand its opposite arms provided.

with a ertures a shaft 'ournaled in said i 7.

apertures and provided with a hand crank by which it may be rotated, one of said arms beingprovided withan additional aperture adapted to receive one of the breaker points and a grinding disk secured to the shaft and extended beyond the additional opening adapted to be inserted between the same when the shaft is rotated.

HERBERT n. WALTERS.

05 In witness whereof I have hereunto set my hand this 17th day of'December 1931. 

